1. Field of the Invention
The present invention relates to a cosmetic cleansing gel which comprises myreth sulfate, cocamidopropyl betaine, cross-linked acrylate copolymer and water.
2. Discussion of Background Information
The desire for clean skin probably is as old as mankind because dirt, sweat and residues of dead skin are ideal media for the growth of all kinds of pathogens and parasites. The joy in body hygiene was continuously increased when it became possible in the 1960's to formulate, in addition to “classic” soaps, liquid cleansing agents with newly developed synthetic surfactants. Since then, bathing and showering have become an integral part of our daily life. Today consumers can choose from a large variety of products for cleansing the different parts of the body.
A special group of skin cleansing products are the facial cleansing products. Since facial skin is particularly sensitive, products which are especially mild and non-irritant to skin are employed for cleansing facial skin. In most cases, gels, i.e., semi-solid, more or less transparent systems are used for this purpose.
Cleansing gels contain water, surfactants and thickeners (gelling agents) as main constituents.
The surfactants are the detersive substances in the cleansing gels. Due to their specific molecule structure with both hydrophilic (water attracting) and hydrophobic (water repellent) groupings in the same molecule they are capable of reducing the surface tension of water, thereby facilitating the removal of dirt. Depending on their charge, the surfactants are classified as anionic, cationic, non-ionic and amphoteric. Due to their capability of reducing the surface tension of water, surfactants bring about a foaming of the preparation.
The thickeners, also called gel formers, form a three-dimensional network in the cleansing gel, in which network the liquid (usually water) is immobilized. Apart from salts, polymers such as polyacrylates are most frequently employed as thickeners. These polymers are added to the preparation to be thickened at a neutral pH, and subsequently they are deprotonated by the addition of base, thereby transforming the preparation into a viscous gel.
Basically, cleansing gels should be both mild and soft to the skin, and should form a sufficient amount of a creamy foam with fine pores. Further, the gels should be as transparent and clear as possible, because thereby it is possible to effectively incorporate therein optical effect materials, and because consumers prefer transparent preparations for esthetic reasons.
Conventional cleansing gels prepared according to the prior art show a number of shortcomings:                In order for the preparation to be mild and to not degrease the skin too much, only selected surfactants in low concentrations can be incorporated into the preparations. Such preparations are, however, not capable of producing sufficient foam. The foam produced is not particularly creamy and does not have fine pores, and collapses within a short period. Also, the viscosity of preparations with a low surfactant concentration cannot be increased in conventional manner by adding salts thereto.        To increase the viscosity of preparations with a low surfactant concentration, polymeric thickeners (e.g., carbopols) have to be added to the preparations. However, such thickeners interfere with the foaming of the preparations.        Usually, the combination of conventional surfactants and polymeric thickeners results in a turbid preparation. Optical effects such as, e.g., the addition of abrasives or glitter substances, are only insufficiently noticeable.        
It would be desirable to overcome the shortcomings of the cleansing gels of the prior art and to provide mild cleansing gels with high foaming power and high transparency.